Add lint action for checkstyle

Reviewed-on: #1
Co-authored-by: Josh Chester <numbers@softwaresmyth.com>
Co-committed-by: Josh Chester <numbers@softwaresmyth.com>

.gitea/workflows/build.yml

@@ -0,0 +1,18 @@
+name: Build with cached gradle
+run-name: Building for ${{ gitea.actor }}
+on: [label]
+
+jobs:
+  Build-with-gradle:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+      - uses: actions/setup-java@v5
+        with:
+          distribution: 'zulu'
+          java-version: '22'
+          cache: 'gradle'
+#          cache-dependency-path: | # optional
+#            sub-project/*.gradle*
+#            sub-project/**/gradle-wrapper.properties
+      - run: ./gradlew build --no-daemon

.gitea/workflows/hello_world.yml

@@ -0,0 +1,19 @@
+name: Gitea Actions Demo
+run-name: ${{ gitea.actor }} is testing out Gitea Actions 🚀
+on: [push]
+
+jobs:
+  Explore-Gitea-Actions:
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "🎉 The job was automatically triggered by a ${{ gitea.event_name }} event."
+      - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by Gitea!"
+      - run: echo "🔎 The name of your branch is ${{ gitea.ref }} and your repository is ${{ gitea.repository }}."
+      - name: Check out repository code
+        uses: actions/checkout@v6
+      - run: echo "💡 The ${{ gitea.repository }} repository has been cloned to the runner."
+      - run: echo "🖥️ The workflow is now ready to test your code on the runner."
+      - name: List files in the repository
+        run: |
+          ls ${{ gitea.workspace }}
+      - run: echo "🍏 This job's status is ${{ job.status }}."

.gitea/workflows/linting.yml

@@ -0,0 +1,54 @@
+name: Java Google Checkstyle
+
+permissions:
+  contents: read
+  pull-request: write
+
+on: [pull_request]
+
+jobs:
+  checkstyle:
+    name: 'Checkstyle Linter'
+    runs-on: ubuntu-latest
+    env:
+      CHECKSTYLE_VERSION: '13.0.0'
+      REVIEWDOG_VERSION: 'latest'
+      REVIEWDOG_GITEA_API_TOKEN: ${{ secrets.REVIEWDOG_TOKEN }}
+      GITEA_ADDRESS: http://gitea:3000
+    steps:
+      - name: 'Pull code'
+        uses: actions/checkout@v6
+
+      - name: 'Find changed Java files'
+        id: changed-files
+        uses: tj-actions/changed-files@v44
+        with:
+          files: |
+            **.java
+
+      - name: 'Setup Java JDK'
+        uses: actions/setup-java@v4
+        with:
+          java-version: '22'
+          distribution: 'zulu'
+
+      - name: 'Setup Reviewdog'
+        uses: reviewdog/action-setup@v1
+        with:
+          reviewdog_version: latest
+#          reviewdog_version: ${{ env.REVIEWDOG_VERSION }}
+
+      - name: 'Run Checkstyle with Reviewdog'
+        if: steps.changed-files.outputs.any_changed == 'true'
+        run: |
+          wget https://github.com/checkstyle/checkstyle/releases/download/checkstyle-${{ env.CHECKSTYLE_VERSION }}/checkstyle-${{ env.CHECKSTYLE_VERSION }}-all.jar
+          
+          echo "Changed files:"
+          echo "${{ steps.changed-files.outputs.all_changed_files }}"
+
+          java -jar checkstyle-${{ env.CHECKSTYLE_VERSION }}-all.jar -c google_checks.xml -f xml ${{ steps.changed-files.outputs.all_changed_files }} \
+          | reviewdog -f=checkstyle \
+          -name="Checkstyle" \
+          -reporter="gitea-pr-review" \
+          -level="warning" \
+          -fail-on-error="true"

src/main/java/com/softwaresmyth/functions/OrNot.java

@@ -2,18 +2,35 @@ package com.softwaresmyth.functions;
 
 import java.util.Optional;
 
-public class OrNot
+/**
+ * Utility class holding the library's methods.
+ */
+public enum OrNot
 {
+    ; // Enum with no variants for a utility class that is not meant to be instantiated.
+
+    /**
+     * Method that does nothing.
+     * It fits any method signature that returns void.
+     */
     public static void noop(Object... ignored)
     {
         //do nothing
     }
 
+    /**
+     * Method that does nothing.
+     * It fits any method signature that does not return void.
+     */
     public static <T> T returnNull(Object... ignored)
     {
         return null;
     }
 
+    /**
+     * Method that does nothing.
+     * It fits any method signature that returns {@link Optional} for any type.
+     */
     public static <T> Optional<T> returnEmpty(Object... ignored)
     {
         return Optional.empty();